The invention relates in general to gun launched ammunition and in particular to gun launched canister ammunition.
Antipersonnel/canister cartridges have been produced for 105 mm caliber and other gun calibers since cannons came into use. The basic principle of antipersonnel/canister cartridges is the expulsion of a large number of lethal fragments, flechettes or other geometric shape objects. The various objects are accelerated during gun launch or during a detonation of an explosive charge to achieve a lethal velocity or the kinetic energy needed to accomplish suppression of troops, targets, or material obstacles. Typically a distinction is made between antipersonnel cartridges which implement an explosive fuze for dispersion, and canister cartridges that spread via mechanical, aerodynamic, or inertial forces.
Several types of canister (no fuze) projectiles have been developed. These canister projectiles employ a cup type design to carry the lethal mechanisms during the cannon launch. This concept has been employed for a number of years in shotgun ammunition, 90 mm ammunition and more recently in 120 mm smooth bore ammunition. Upon exit of the gun, the lethal mechanisms are dispersed by the resultant gun forces and acted upon by aerodynamic forces so as to disperse the sub-projectiles in a pattern. The sub-projectiles then travel ballistically until impact with the target of interest.
An important aspect of canister cartridge performance is to deploy the lethal mechanisms in a desired pattern, while assuring a density of sub projectiles that produce the desired end effect. U.S. Pat. No. 6,701,848 discloses a 105 mm canister cartridge that disperses a payload of sub-projectiles via gun launch and aerodynamic forces. However, the single dispersion cone angle that is produced does not provide sufficient density across all required ranges to fulfill the current lethality need. The present invention is a dual spin projectile that improves sub-projectile density across required ranges.